Smart 2DH bus negotiation speeds

[Aeron Barhorst]

I have a client running a Smart 2DH array controller in some RAID 5 arrays. Some of the drives were recently upgraded, but non-compaq branded drives were used.
The controller refuses to negotiate the ultra scsi protocol with the non-compaq drives, even though they are ultra-wide drives. I have hooked up an assortment of Compaq brand drives for testing and they all negotiate the ultra protocol. (In the compaq array manager under physical drive properties, the transfer speed indicates "ultra". The non compaq drives are listed as "fast").

It almost looks like Compaq deliberatly coded this.
Is their a way arround this (i.e. older firmware or driver, or registry setting?